In any aircraft, one or more engines can drop out, notably on take-off.
In case of engine outage on take-off, a specific trajectory is defined (trajectory or procedure called EOSID for Engine Out—SID), by contrast with the standard departure procedure without outage called SID.
For the current aircraft, the EOSID trajectories are defined by the airlines for each type of carrier using performance computation tools supplied by the aircraft manufacturers, covered by the civil aviation authorities of the country concerned, to manage the engine outage situations on take-off. These procedures are stored in the navigation databases and are associated with a runway.
The EOSID trajectories generally aim to find a lateral trajectory that makes it possible to avoid obstacles, with a climb gradient that is degraded (because of the engine outage).
Generally, to characterize such EOSID trajectories, aeronautical practices consider a point called point of “divergence”. If this (lateral) trajectory point exists, it is a point from which the EOSID diverges from the SID in terms of “coding” of legs (i.e. of flight plan segments).
Another point is called “disarm” point, and can be defined by the “Disarm Point” according to the ARINC 424 aeronautical standard. This point associated with an EOSID procedure can be used as spatial reference, once sequenced, for the deactivation of the automatic insertion of the EOSID procedure in case of engine outage.
Several technical problems arise with respect to the use of these EOSID trajectories.
In case of engine outage on take-off, if an EOSID is defined, a temporary flight plan is proposed to the pilot. The temporary flight plan makes it possible to rejoin that of the EOSID, as long as the aeroplane is on the common part of the trajectories of the SID (Standard Instrument Departure procedure) and the EOSID (Engine Out—SID procedure). The pilot therefore has the responsibility of accepting or rejecting this temporary flight plan, without, however, knowing, in certain situations, if he or she could follow the standard procedure in safety (according to the aeroplane performance levels, the relief, etc.).
Moreover, once on board, the pilot does not have the option to modify an EOSID procedure, which is associated with a runway. Now, on a same runway, several departure procedures may be possible. In certain cases, the EOSID will not be compatible with the leg coding characteristics (e.g. course, etc.) of the active take-off procedure although the pilot will have to fly it if an engine outage is declared. In this precise case, the procedure will not be activated and the pilot must manually follow this procedure.
In other words, the safe procedures in case of engine outage (EOSID) do not exist for all departures. Only some airlines create these procedures for certain airports for each type of aeroplane. These procedures must be checked every 28 days and potentially redefined if the linked departure procedure is modified even very slightly. It should be noted that the engine outage procedure is systematically prepared for each departure. These days, the pilots draw the procedure on a paper or electronic medium and retain this procedure throughout the departure procedure.
The use of the procedures is in fact limited in the current aircraft. The size of the database, the work load of the airline necessary to the construction of the procedure and the maintenance of this procedure according to the new aeroplane performance databases or navigation databases (delivered every 28 days), often limit the use of these procedures.
In the current aircraft, an EOSID procedure is automatically proposed only if the engine outage is detected before the point of divergence between the standard take-off procedure (SID) and the take-off procedure in case of engine outage (EOSID). Consequently, if the engine outage is detected after the point of divergence, the EOSID is not proposed automatically and the pilot must define it manually in a stress situation. This aspect is problematical notably in case of an error present in the navigation database (for example in case of updating of the SID and not of the EOSID) where a point of divergence would no longer be defined.
The patent literature, for example FR2953301, does not provide appropriate solutions for the technical problems mentioned.
There is a need for procedures and systems that make it possible to assist the pilot in an engine outage procedure on take-off.